The present disclosure generally relates to systems and methods of oil scavenging systems in an aircraft engine. More particularly, this disclosure relates to closed loop oil scavenge systems within the sump of the gas turbine engine that includes an integrated heat exchanger.
At least some known gas turbine engines, such as turbofans, include a fan, a core engine, and a power turbine. The core engine includes at least one compressor, a combustor, and a high-pressure turbine coupled together in a serial flow relationship. More specifically, the compressor and high-pressure turbine are coupled through a shaft to form a high-pressure rotor assembly. Air entering the combustor is mixed with fuel and ignited to form a high energy gas stream. The high energy gas stream flows through the high-pressure turbine to rotatably drive the high-pressure turbine such that the shaft rotatably drives the compressor. The gas stream expands as it flows through a power or low-pressure turbine positioned aft of the high-pressure turbine. The low-pressure turbine includes a rotor assembly having a fan coupled to a drive shaft. The low-pressure turbine rotatably drives the fan through the drive shaft.
The compressor and the turbine are generally coupled through one or more shafts. Additionally, rotation of certain components of the compressor, turbine, and the one or more shafts is facilitated by a plurality of bearings. These bearings are provided with lubrication oil throughout operation of the gas turbine engine to, e.g., remove heat from such bearings and reduce an amount of friction within such bearings.
At least some known gas turbine engines include a lubrication oil circulation assembly for providing lubrication oil to each of the plurality of bearings, and further for pumping out, or scavenging, lubrication oil from one or more sumps provided for collecting and/or containing such lubrication oil. The lubrication oil circulation assembly typically includes at least one pump, a heat exchanger positioned outside of the core air flowpath, and one or more supply lines or scavenge lines extending through the core air flowpath to reach, e.g., the bearings and the one or more sumps. However, the supply lines and scavenge lines extending through the core air flowpath may disrupt an airflow through the core air flowpath. Accordingly, a means for reducing a size and/or amount of lubrication oil supply lines and/or scavenge lines extending through the core air flowpath is desired.